nvme-print: add show_key_value print_ops

This is to output a command result as json key and value.

Signed-off-by: Tokunori Ikegami <[email protected]>

Author: ikegami-t

nvme-print-binary.c

@@ -435,6 +435,7 @@ static struct print_ops binary_print_ops = {
 	.show_perror			= NULL,
 	.show_status			= NULL,
 	.show_error_status		= NULL,
+	.show_key_value			= NULL,
 };
 
 struct print_ops *nvme_get_binary_print_ops(nvme_print_flags_t flags)

nvme-print-json.c

@@ -4900,6 +4900,20 @@ static void json_output_perror(const char *msg, va_list ap)
 	json_output_object(r);
 }
 
+static void json_output_key_value(const char *key, const char *val, va_list ap)
+{
+	struct json_object *r = json_r ? json_r : json_create_object();
+
+	_cleanup_free_ char *value = NULL;
+
+	if (vasprintf(&value, val, ap) < 0)
+		value = NULL;
+
+	obj_add_str(r, key, value ? value : "Could not allocate string");
+
+	obj_print(r);
+}
+
 void json_show_init(void)
 {
 	json_r = json_create_object();
@@ -5264,6 +5278,7 @@ static struct print_ops json_print_ops = {
 	.show_perror			= json_output_perror,
 	.show_status			= json_output_status,
 	.show_error_status		= json_output_error_status,
+	.show_key_value			= json_output_key_value,
 };
 
 struct print_ops *nvme_get_json_print_ops(nvme_print_flags_t flags)

nvme-print-stdout.c

@@ -5705,6 +5705,16 @@ static void stdout_perror(const char *msg, va_list ap)
 	perror(error);
 }
 
+static void stdout_key_value(const char *key, const char *val, va_list ap)
+{
+	_cleanup_free_ char *value = NULL;
+
+	if (vasprintf(&value, val, ap) < 0)
+		value = NULL;
+
+	printf("%s: %s\n", key, value ? value : "Could not allocate string");
+}
+
 static void stdout_discovery_log(struct nvmf_discovery_log *log, int numrec)
 {
 	int i;
@@ -6052,6 +6062,7 @@ static struct print_ops stdout_print_ops = {
 	.show_perror			= stdout_perror,
 	.show_status			= stdout_status,
 	.show_error_status		= stdout_error_status,
+	.show_key_value			= stdout_key_value,
 };
 
 struct print_ops *nvme_get_stdout_print_ops(nvme_print_flags_t flags)

nvme-print.c

@@ -1586,6 +1586,22 @@ void nvme_show_perror(const char *msg, ...)
 	va_end(ap);
 }
 
+void nvme_show_key_value(const char *key, const char *val, ...)
+{
+	struct print_ops *ops = nvme_print_ops(NORMAL);
+	va_list ap;
+
+	va_start(ap, val);
+
+	if (nvme_is_output_format_json())
+		ops = nvme_print_ops(JSON);
+
+	if (ops && ops->show_key_value)
+		ops->show_key_value(key, val, ap);
+
+	va_end(ap);
+}
+
 void nvme_show_discovery_log(struct nvmf_discovery_log *log, uint64_t numrec,
 			     nvme_print_flags_t flags)
 {

nvme-print.h

@@ -111,6 +111,7 @@ struct print_ops {
 	void (*show_perror)(const char *msg, va_list ap);
 	void (*show_status)(int status);
 	void (*show_error_status)(int status, const char *msg, va_list ap);
+	void (*show_key_value)(const char *key, const char *val, va_list ap);
 
 	nvme_print_flags_t flags;
 };
@@ -334,6 +335,7 @@ void nvme_show_perror(const char *msg, ...);
 void nvme_show_error_status(int status, const char *msg, ...);
 void nvme_show_init(void);
 void nvme_show_finish(void);
+void nvme_show_key_value(const char *key, const char *value, ...);
 bool nvme_is_fabrics_reg(int offset);
 bool nvme_is_fabrics_optional_reg(int offset);
 bool nvme_registers_cmbloc_support(__u32 cmbsz);